MathDB

P1- Combinatorics from 2017 Iran MO 3rd round

Source: 2017 Iran MO 3rd round, first combinatorics exam P1

September 12, 2017

Irancombinatorics

Problem Statement

There's a tape with

n^2

cells labeled by

1,2,\ldots,n^2

. Suppose that

x,y

are two distinct positive integers less than or equal to

n

. We want to color the cells of the tape such that any two cells with label difference of

x

y

have different colors. Find the minimum number of colors needed to do so.